Not to be confused with crating, the act of crating it up, from the infinitive "to crate it up" refers to the pre-purchasing of crates of beer (or, on occasion, of other alcoholic beverages) for a party.

Dude 1: Hey dude, what're you up to this afternoon?
Dude 2: Ahh, I'm crating it up before Jessica's party, it's set to be a good night.